Power supply method, power supply device, and base station

ABSTRACT

A method includes receiving currents supplied by a power generation apparatus, distributing the currents supplied by the power generation apparatus to a load and a lithium ion battery to ensure normal running of the load and enable the lithium ion battery to be charged. After the lithium ion battery is fully charge, the currents supplied by the power generation apparatus are distributed to the lead acid battery so that the lead acid battery is charged.

This application is a continuation of U.S. application Ser. No.13/625,310, filed on Sep. 24, 2012, which is a continuation ofInternational Application No. PCT/CN2012/078982, filed on Jul. 20, 2012,which claims priority to Chinese Patent Application No. 201210050087.4,filed on Feb. 29, 2012. The afore-mentioned patent applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communications and, inparticular embodiments, to a power supply method, a power supply device,and a base station.

BACKGROUND

A base station is an indispensable transceiver apparatus in moderncommunication. In some remote and undeveloped regions, mains powersupply is poor, and power interruption frequently occurs, resulting inworking suspension of the base station. Therefore, a power generationsystem and a backup power system need to be provided for base stationsin the regions where the mains power supply is poor or no mains powersupply is available. In the prior art, oil machine power generation,solar power generation, or wind power generation is generally used as apower generation system to supply power to base stations. The solarpower generation is the most environmentally friendly, and achieves morestable power generation.

An existing base station typically uses multiple sets of solarphotovoltaic modules for power generation, and uses a lead acid batteryas a backup power source for storing electrical energy, and uses anelectrical energy controller to schedule and control the entire powersupply device.

In the case of illumination, the solar photovoltaic module convertssolar energy into electrical energy to supply power to a load of thebase station, and meanwhile charging the lead acid battery. In the caseof no illumination, the lead acid battery supplies power to the load ofthe base station.

In the prior art, in-depth charge and discharge fails to be achieved forthe lead acid battery. If the in-depth charge and discharge is performedon the lead acid battery, the life cycle of the battery is greatlyshortened, thereby shortening the maintenance duration and increasingthe maintenance cost. In addition, the charge speed of the lead acidbattery is very low. If a power failure occurs during charge, the leadacid battery fails to function as a backup power source. A base stationgenerally requires that a backup power source be used for three to fivedays. In-depth charge and discharge cannot be achieved, and therefore,available electrical energy in the battery is restricted. To satisfy therequirement, the base station must be provided with a large-capacitylead acid battery, which increases investment costs. However, thecurrent base station is not provided with other power systems, andtherefore the load of the base station has to suspend working when theelectrical energy in the lead acid battery is exhausted.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a power supply method, apower supply device, and a base station, which, while satisfying userequirements of a backup power source, prolong the life cycle of a leadacid battery, reduce the set capacity of the original lead acid battery,and thereby reduce investment costs.

In one aspect, a power supply method is provided, including, receivingcurrents supplied by a power generation apparatus, transferring currentsrequired by a load among the currents to the load, and transferringremaining currents of the currents except the currents required by theload among the currents to a lithium ion battery so that the lithium ionbattery is charged, monitoring a voltage of the lithium ion battery, andwhen the voltage of the lithium ion battery increases to a first presetvoltage, sending a switching signal to a zero-time switching unitconnected to the lithium ion battery and a lead acid battery to enablethe zero-time switching unit to non-intermittently switch an energystorage unit connected to an electrical energy controller from thelithium ion battery to the lead acid battery, and enable the electricalenergy controller to transfer the remaining currents to the lead acidbattery so that the lead acid battery is charged, where the first presetvoltage is the voltage of the lithium ion battery corresponding to 95%to 100% of the capacity of the lithium ion battery, monitoring thecurrents supplied by the power generation apparatus, and when thecurrents supplied by the power generation apparatus are zero, sending aswitching signal to the zero-time switching unit to enable thezero-switching unit to non-intermittently switch the energy storage unitconnected to the electrical energy controller from the lead acid batteryto the lithium ion battery, so that a current provided by the lithiumion battery is transferred to the load, and monitoring the voltage ofthe lithium ion battery, and when the voltage of the lithium ion batterydecreases to a second preset voltage, sending a switching signal to thezero-time switching unit to enable the zero-time switching unit tonon-intermittently switch the energy storage unit connected to theelectrical energy controller from the lithium ion battery to the leadacid battery, so that a current provided by the lead acid battery istransferred to the load, where the second preset voltage is the voltageof the lithium ion battery corresponding to 0% to 20% of the capacity ofthe lithium ion battery.

In another aspect, a power supply device is provided, including a leadacid battery and further including, an electrical energy control unit,configured to receive currents supplied by a power generation apparatus,distribute the currents supplied by the power generation apparatus to aload and a lithium ion battery to ensure normal running of the load andenable the lithium ion battery to be charged, and when the lithium ionbattery is fully charged, distribute the currents supplied by the powergeneration apparatus to the lead acid battery so that the lead acidbattery is charged. When the electrical energy control unit detects thatthe currents supplied by the power generation apparatus are interrupted,the electrical energy control module is further configured to firsttransfer a current provided by the lithium ion battery to the load, andtransfer a current provided by the lead acid battery to the load whenthe lithium ion battery is exhausted, and the lithium ion battery.

The electrical energy control unit is connected to the load of the basestation, a monitoring unit, and a zero-time switching unit. Themonitoring unit is further connected to the zero-time switching unit andthe lithium ion battery. The zero-time switching unit is furtherconnected to the lithium ion battery and the lead acid battery.

In another aspect, a base station is further provided, including, thepower supply device, configured to supply currents to a load of the basestation to ensure normal running of the base station, and a transceiverdevice, configured to receive or transmit a signal, and a controldevice, configured to control the transceiver device to receive ortransmit a signal.

According to the power supply method, the power supply device, and thebase station provided in the embodiments of the present invention, alithium ion battery that can be fast charged and discharged and haslarge discharge depth is added, which reduces the charge and dischargetimes for a lead acid battery. This prolongs the life cycle of the leadacid battery while satisfying use requirements of a backup power source,reduces the set capacity of the original lead acid battery, and therebyreduces investment costs.

BRIEF DESCRIPTION OF THE DRAWINGS

To illustrate the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflydescribes the accompanying drawings required for describing theembodiments. Apparently, the accompanying drawings in the followingdescriptions show merely some embodiments of the present invention, andpersons of ordinary skill in the art can derive other drawings from theaccompanying drawings without creative efforts.

FIG. 1 is a first schematic flow chart of a power supply methodaccording to an embodiment of the present invention;

FIG. 2 is a second schematic flow chart of a power supply methodaccording to an embodiment of the present invention;

FIG. 3 is a first schematic structural diagram of a power supply deviceaccording to an embodiment of the present invention;

FIG. 4 is a second schematic structural diagram of a power supply deviceaccording to an embodiment of the present invention;

FIG. 5 is a third schematic structural diagram of a power supply deviceaccording to an embodiment of the present invention; and

FIG. 6 is a schematic structural diagram of a base station according toan embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following clearly and completely describes the technical solutionsaccording to the embodiments of the present invention with reference tothe accompanying drawings in the embodiments of the present invention.Apparently, the embodiments in the following description are merely apart rather than all of the embodiments of the present invention. Allother embodiments obtained by persons of ordinary skill in the art basedon the embodiments of the present invention without creative effortsshall fall within the protection scope of the present invention.

Embodiment 1

The present invention provides a power supply method, as shown in FIG.1, including the following steps.

S101. Receive currents supplied by a power generation apparatus,transfer currents required by a load among the currents to the load, andtransfer the remaining currents except the currents required by the loadamong the currents to a lithium ion battery so that the lithium ionbattery is charged.

S102. Monitor the voltage of the lithium ion battery, and when thevoltage of the lithium ion battery increases to a first preset voltage,send a switching signal to a zero-time switching unit connected to thelithium ion battery and a lead acid battery to enable the zero-timeswitching unit to non-intermittently switch an energy storage unitconnected to an electrical energy controller from the lithium ionbattery to the lead acid battery, and enable the electrical energycontroller to transfer the remaining currents to the lead acid batteryso that the lead acid battery is charged, where the first preset voltageis the voltage of the lithium ion battery corresponding to 95% to 100%of the capacity of the lithium ion battery.

S103. Monitor the currents supplied by the power generation apparatus,and when the currents supplied by the power generation apparatus arezero, send a switching signal to the zero-time switching unit to enablethe zero-switching unit to non-intermittently switch the energy storageunit connected to the electrical energy controller from the lead acidbattery to the lithium ion battery, so that a current provided by thelithium ion battery is transferred to the load.

S104. Monitor the voltage of the lithium ion battery, and when thevoltage of the lithium ion battery decreases to a second preset voltage,send a switching signal to the zero-time switching unit to enable thezero-time switching unit to non-intermittently switch the energy storageunit connected to the electrical energy controller from the lithium ionbattery to the lead acid battery, so that a current provided by the leadacid battery is transferred to the load, where the second preset voltageis the voltage of the lithium ion battery corresponding to 0% to 20% ofthe capacity of the lithium ion battery.

According to the power supply method provided in this embodiment, alithium ion battery that can be fast charged and discharged and haslarge discharge depth is added, which reduces the charge and dischargetimes for a lead acid battery. This prolongs the life cycle of the leadacid battery while satisfying use requirements of a backup power source,reduces the set capacity of the original lead acid battery, and therebyreduces investment costs.

Embodiment 2

The present invention provides a power supply method, including a chargeprocess and a discharge process. As shown in FIG. 2, the charge processincludes the following steps.

S201. Receive currents supplied by a power generation apparatus, andtransfer currents required by a load among the currents to the load.

Specifically, a power supply device receives the currents supplied bythe power generation apparatus by using an electrical energy controller,and transfers the currents required by the load among the receivedcurrents to the load by using a cable to ensure normal running of adevice. Certainly, the currents required by the load are not fixed, andneed to be determined according to the condition of the load.

The currents supplied by the power generation apparatus include:currents generated using solar energy, currents generated using thermalenergy from combustion of fuel, electrical energy generated using windenergy, and/or currents supplied by the mains. To be specific, thereceived currents may include any one of the four types of currents, andmay also be a combination of any two or three types of the currents, ora combination of the four types of currents.

S202. The electrical energy controller transfers the remaining currentsexcept the currents required by the load among the currents to a lithiumion battery so that the lithium ion battery is charged.

S203. Monitor the voltage of the lithium ion battery, and determinewhether the voltage of the lithium ion battery reaches a first presetvoltage. When the voltage of the lithium ion battery increases to thefirst preset voltage, step S204 is performed. When the voltage of thelithium ion battery does not increase to the first preset voltage, stepS202 is performed. The first preset voltage is the voltage of thelithium ion battery corresponding to 95% to 100% of the capacity of thelithium ion battery.

S204: Send a switching signal to a zero-time switching unit connected tothe lithium ion battery and a lead acid battery to enable the zero-timeswitching unit to non-intermittently switch an energy storage unitconnected to the electrical energy controller from the lithium ionbattery to the lead acid battery.

S205. The electrical energy controller transfers the remaining currentsto the lead acid battery. After being fully charged, the lead acidbattery enters the standby state, and the remaining currents are stilltransferred to the lead acid battery to maintain it in the floatingcharge state.

As shown in FIG. 2, the discharge process includes the following steps.

S206. Monitor the currents supplied by the power generation apparatus,determine whether the power supply is interrupted according to whetherthe currents supplied by the power generation apparatus are zero. Whenthe currents supplied by the power generation apparatus are zero, stepS207 is performed. When the currents supplied by the power generationapparatus are not zero, step S205 is performed.

S207. Send a switching signal to the zero-time switching unit to enablethe zero-time switching unit to non-intermittently switch the energystorage unit connected to the electrical energy controller from the leadacid battery to the lithium ion battery.

S208. The electrical energy controller transfers a current provided bythe lithium ion battery to the load.

S209. Monitor the voltage of the lithium ion battery, and determinewhether the voltage of the lithium ion battery decreases to a secondpreset voltage. When the voltage of the lithium ion battery decreases tothe second preset voltage, step S2010 is performed. When the voltage ofthe lithium ion battery does not decrease to the second preset voltage,step S208 is performed. The second preset voltage is the voltage of thelithium ion battery corresponding to 0% to 20% of the capacity of thelithium ion battery.

S2010. Send a switching signal to the zero-time switching unit to enablethe zero-time switching unit to non-intermittently switch the energystorage unit connected to the electrical energy controller from thelithium ion battery to the lead acid battery.

S2011. The electrical energy controller transfers a current provided bythe lead acid battery to the load.

A lithium ion battery has advantages of fast charge, more charge anddischarge times, a long life cycle, and large discharge depth.Therefore, a lithium ion battery is added based on the current lead acidbattery. This greatly shortens the charge time for a backup power sourceand improves the emergency-handling capability. In addition, in the caseof power interruption, the lithium ion battery is preferentially used,and the lead acid battery is not used before the electrical energy ofthe lithium ion battery is exhausted. In this way, in the case ofshort-period power interruption, a power supply requirement may besatisfied by using only the lithium ion battery, thereby reducing theuse frequency of the lead acid battery, prolonging the life cycle of thelead acid battery, and increasing the maintenance duration of the powersupply device. Moreover, a combination of the lithium ion battery andthe lead acid battery may greatly reduce the set capability of the leadacid battery, thereby reducing investment costs.

Further, the zero-time switching unit is used to perform switchingbetween the lithium ion battery and the lead acid battery. Therefore,when the lithium ion battery is exhausted, a power supply unit isnon-intermittently switched from the lithium ion battery to the leadacid battery, thereby enabling the backup power source to constantlysupply power to the load, and ensuring stable power supply.

In this embodiment, the lead acid battery may be an Absorptive GlassMat, absorptive glass mat (AGM) type or GEL (gel) type lead acidbattery, and the lithium ion battery may be replaced with another typeof battery that can be fast charged, and has many charge and dischargetimes, and large discharge depth.

The method may be applied to a communication base station, and may alsobe applied to other devices requiring a backup power source.

According to the power supply method provided in this embodiment, alithium ion battery that can be fast charged and discharged and haslarge discharge depth is added, which reduces the charge and dischargetimes for a lead acid battery. This prolongs the life cycle of the leadacid battery while satisfying use requirements of a backup power source,reduces the set capacity of the original lead acid battery, and therebyreduces investment costs.

Embodiment 3

The present invention provides a power supply device 01, including alead acid battery 011, and as shown in FIG. 3, further including, anelectrical energy control unit 012, configured to receive currentssupplied by a power generation apparatus, distribute the currentssupplied by the power generation apparatus to a load and a lithium ionbattery to ensure normal running of the load and enable the lithium ionbattery to be charged, and when the lithium ion battery is fullycharged, distribute the currents supplied by the power generationapparatus to the lead acid battery so that the lead acid battery ischarged. When the electrical energy control unit detects that thecurrents supplied by the power generation apparatus are interrupted, theelectrical energy control module is further configured to first transfera current provided by the lithium ion battery to the load, and thentransfer a current provided by the lead acid battery to the load whenthe lithium ion battery is exhausted, and the lithium ion battery 013.

Further, as shown in FIG. 4, the electrical energy control unit 012includes an electrical energy controller 0121, a monitoring unit 0122,and a zero-time switching unit 0123.

The electrical energy controller 0121 is configured to receive currentssupplied by the power generation apparatus, transfer currents requiredby the load among the currents to the load, and transfer the remainingcurrents except the currents required by the load among the currents tothe lithium ion battery 013 so that the lithium ion battery 013 ischarged.

The monitoring unit 0122 is configured to monitor the voltage of thelithium ion battery 013, and when the voltage of the lithium ion battery013 increases to a first preset voltage, send a switching signal to thezero-time switching unit 0123 connected to the lithium ion battery 013and the lead acid battery 011 to enable the zero-time switching unit0123 to non-intermittently switch an energy storage unit connected tothe electrical energy controller 0121 from the lithium ion battery 013to the lead acid battery 011, and enable the electrical energycontroller 0121 to transfer the remaining currents to the lead acidbattery 011 so that the lead acid battery 011 is charged, where thefirst preset voltage is the voltage of the lithium ion battery 013corresponding to 95% to 100% of the capacity of the lithium ion battery013.

The monitoring unit 0122 is further configured to monitor the currentssupplied by the power generation apparatus, and when the currentssupplied by the power generation apparatus are zero, send a switchingsignal to the zero-time switching unit 0123 to enable the zero-switchingunit 0123 to non-intermittently switch the energy storage unit connectedto the electrical energy controller 0121 from the lead acid battery 011to the lithium ion battery 013, so that a current provided by thelithium ion battery 013 is transferred to the load.

The monitoring unit 0122 is further configured to monitor the voltage ofthe lithium ion battery 013, and when the voltage of the lithium ionbattery 013 decreases to a second preset voltage, send a switchingsignal to the zero-time switching unit 0123 to enable the zero-timeswitching unit 0123 to non-intermittently switch the energy storage unitconnected to the electrical energy controller 0121 from the lithium ionbattery 013 to the lead acid battery 011, so that a current provided bythe lead acid battery 011 is transferred to the load, where the secondpreset voltage is the voltage of the lithium ion battery 013corresponding to 0% to 20% of the capacity of the lithium ion battery013.

The zero-time switching unit 0123 is configured to non-intermittentlyswitch the energy storage unit connected to the electrical energycontroller 0121 between the lithium ion battery 013 and the lead acidbattery 011.

As shown in FIG. 4, the electrical energy controller 0121 is connectedto the load of the base station, the monitoring unit 0122, and thezero-time switching unit 0123. The monitoring unit 0122 is connected tothe zero-time switching unit 0123 and the lithium ion battery 013. Thezero-time switching unit 0123 is connected to the lithium ion battery013 and the lead acid battery 011.

Further, as shown in FIG. 5, the power supply device further includes apower generation apparatus 010, configured to supply electrical energyto the load. The power generation apparatus 010 includes a solarphotovoltaic module, a wind power generation module, an oil machinepower generation module, and/or a mains power supply module. To bespecific, the power generation apparatus 010 may include any one of thefour modules, and may also be a combination of any two or three of themodules, or a combination of the four modules, the solar photovoltaicmodule is configured to generate currents using solar energy. The windpower generation module is configured to generate currents using windenergy. The oil machine power generation module is configured togenerate currents using thermal energy from combustion of fuel. Themains power supply module is configured to receive currents supplied bythe mains, and a battery management system (BMS) 014, configured toprotect the lithium ion battery 013. The lithium ion battery includes aplurality of monomer batteries. During charge, the case of chargenon-equalization of the monomer batteries often occurs. However, the BMSis capable of enabling charge equalization of the monomer batteries inthe lithium ion battery 013, and preventing damage caused byover-charge, over-discharge and over-temperature of the lithium ionbattery 013, thereby prolonging the life cycle of the battery.

As shown in FIG. 5, the power generation apparatus 010 is connected tothe electrical energy controller 0121. The BMS 014 is connected to themonitoring unit 0122, the zero-time switching unit 0123, and the lithiumion battery 013.

In this embodiment, the lead acid battery may be an Absorptive GlassMat, absorptive glass mat (AGM) type or GEL (gel) type lead acidbattery, and the lithium ion battery may be replaced with another typeof battery that can be fast charged, and has many charge and dischargetimes, and large discharge depth.

The power supply device provided in this embodiment may be applied to acommunication base station, and may also be applied to other devicesrequiring a backup power source.

According to the power supply device provided in this embodiment, alithium ion battery is added, which prevents floating charge for a leadacid battery, prolongs the life cycle of the lead acid battery, reducesthe set capacity of the original lead acid battery, and thereby reducesoperation costs. In addition, the power source for power supply isnon-intermittently switched from the lithium ion battery to the leadacid battery when the lithium ion battery is exhausted, preventing thepower supply from interruption, and thereby improving the reliability ofthe power supply device.

An embodiment of the present invention further provides a base station1, as shown in FIG. 6, including the power supply device 01 describedabove, configured to supply electrical energy to the base station toensure normal running of the base station.

The base station 1 further includes a load 02 of the base station,including a transceiver device 021, configured to receive or transmit asignal and a control device 022, configured to control the transceiverdevice to receive or transmit a signal.

Adding of a lithium ion battery greatly shortens the charge time for abackup power source and improves the emergency-handling capability. Inaddition, in the case of power interruption, the lithium ion battery ispreferentially used, and the lead acid battery is not used before theelectrical energy of the lithium ion battery is exhausted. In this way,in the case of short-period power interruption, a power supplyrequirement may be satisfied by using only the lithium ion battery,thereby reducing the use frequency of the lead acid battery, prolongingthe life cycle of the lead acid battery, and increasing the maintenanceduration of the power supply device. Moreover, a combination of thelithium ion battery and the lead acid battery may greatly reduce the setcapability of the lead acid battery, thereby reducing investment costs.

Further, the zero-time switching unit is configured to perform switchingbetween the lithium ion battery and the lead acid battery. Therefore,when the lithium ion battery is exhausted, a power supply unit isnon-intermittently switched from the lithium ion battery to the leadacid battery, thereby enabling the backup power source to constantlysupply power to the load of the base station, and ensuring stablerunning of the base station.

The foregoing descriptions are merely exemplary embodiments of thepresent invention, but not intended to limit the present invention. Anyvariation or replacement made by persons skilled in the art withoutdeparting from the spirit of the present invention shall fall within theprotection scope of the present invention. Therefore, the protectionscope of the present invention shall be subject to the protection scopeof the claims.

What is claimed is:
 1. A base station, comprising: a power supplydevice, configured to supply currents to a load of the base station toensure normal running of the base station, the load of the base stationcomprising a transceiver device, configured to receive or transmit asignal; and a control device, configured to control the transceiverdevice to receive or transmit the signal; wherein the power supplydevice comprises: a lead acid battery; a lithium ion battery; and anelectrical energy control unit, configured to receive currents suppliedby a power generation apparatus, distribute the currents supplied by thepower generation apparatus to the load and the lithium ion battery toensure normal running of the load and to enable the lithium ion batteryto be charged, and when the lithium ion battery is fully charged, todistribute the currents supplied by the power generation apparatus tothe load and the lead acid battery so that the lead acid battery ischarged; wherein when the electrical energy control unit detects thatthe currents supplied by the power generation apparatus are interrupted,the electrical energy control unit is further configured to firsttransfer a current provided by the lithium ion battery to the load, andthen transfer a current provided by the lead acid battery to the loadwhen the lithium ion battery is exhausted.
 2. The base station accordingto claim 1, wherein the electrical energy control unit comprises: anelectrical energy controller, configured to receive the currentssupplied by the power generation apparatus, to transfer currentsrequired by the load among the currents to the load, and to transferremaining currents except the currents required by the load among thecurrents to the lithium ion battery so that the lithium ion battery ischarged; a monitoring unit, configured to monitor a voltage of thelithium ion battery, and when the voltage of the lithium ion batteryincreases to a first preset voltage, to send a switching signal to azero-time switching unit connected to the lithium ion battery and thelead acid battery to enable the zero-time switching unit tonon-intermittently switch an energy storage unit connected to theelectrical energy controller from the lithium ion battery to the leadacid battery, and to enable the electrical energy controller to transferremaining currents to the lead acid battery so that the lead acidbattery is charged, wherein the first preset voltage is the voltage ofthe lithium ion battery corresponding to 95% to 100% of a capacity ofthe lithium ion battery; wherein the monitoring unit is furtherconfigured to monitor the currents supplied by the power generationapparatus, and when the currents supplied by the power generationapparatus are zero, to send a switching signal to the zero-timeswitching unit to enable a zero-switching unit to non-intermittentlyswitch the energy storage unit connected to the electrical energycontroller from the lead acid battery to the lithium ion battery, sothat the current provided by the lithium ion battery is transferred tothe load; and the monitoring unit is further configured to monitor thevoltage of the lithium ion battery, and when the voltage of the lithiumion battery decreases to a second preset voltage, to send a switchingsignal to the zero-time switching unit to enable the zero-time switchingunit to non-intermittently switch the energy storage unit connected tothe electrical energy controller from the lithium ion battery to thelead acid battery, so that the current provided by the lead acid batteryis transferred to the load, wherein the second preset voltage is thevoltage of the lithium ion battery corresponding to 0% to 20% of thecapacity of the lithium ion battery; and the zero-time switching unit,configured to non-intermittently switch the energy storage unitconnected to the electrical energy controller between the lithium ionbattery and the lead acid battery.
 3. The base station according toclaim 2, wherein the electrical energy controller is connected to theload of the base station, the monitoring unit, and the zero-timeswitching unit; wherein the monitoring unit is connected to thezero-time switching unit and the lithium ion battery; and wherein thezero-time switching unit is connected to the lithium ion battery and thelead acid battery.
 4. The base station according to claim 1, wherein thepower supply device further comprises a battery management system,configured to protect the lithium ion battery, to enable chargeequalization of the lithium ion battery, and to prevent the lithium ionbattery from over-charge, over-discharge and over-temperature.
 5. Thebase station according to claim 1, wherein the power supply devicefurther comprises the power generation apparatus, configured to supplycurrents to the load.
 6. The base station according to claim 5, whereinthe power generation apparatus comprises a solar photovoltaic module,wherein the solar photovoltaic module is configured to generate thecurrents using solar energy.
 7. The base station according to claim 5,wherein the power generation apparatus comprises a wind power generationmodule, wherein the wind power generation module is configured togenerate the currents using wind energy.
 8. The base station accordingto claim 5, wherein the power generation apparatus comprises a fossilfuel machine power generation module, wherein the fossil fuel machinepower generation module is configured to generate the currents usingthermal energy from combustion of fuel.
 9. The base station according toclaim 5, wherein the power generation apparatus comprises a mains powersupply module, wherein the mains power supply module is configured toreceive currents supplied by the mains.